1. Technical Field
The present invention is directed to a stand for a fluid delivery device, and more particularly toward an integral stand and carrier gas delivery conduit for maintaining a nebulizer in a select orientation.
2. Background Art
Nebulizers are devices for delivering atomized water or medication to air to be inhaled into the lungs of a patient. Most nebulizers are connected in series with a device to supply pressurized air to the patient and the nebulizers have a reservoir to contain the liquid (or in some cases, powder) medication. A variety of nebulizer structures are known in the medical field. An exemplary nebulizer is that disclosed in Lester, U.S. Pat. No. 3,762,409. The nebulizer described in Lester '409 provides an acorn-shaped reservoir so that as the liquid is consumed it is drained toward the converging bottom to the point of the acorn where a liquid inlet to the nebulizer system is located.
Typically a nebulizer of the type described in Lester '409 is used for delivering medication in the form a finely nebulized mist to a patient. Often this medication must be delivered in precise dosages. It is also common for the liquid medication being delivered to be very expensive, costing as much as $100/cc. A nebulizer such as that disclosed in Lester '409 introduces substantially all the liquid medication is introduced into the air supply of the patient if the nebulizer is kept in a vertical orientation. However, often nebulizers are tipped out of their vertical orientation, causing a nebulizer such as that disclosed in Lester '409 to not deliver all the liquid medication to a patient.
Farr, U.S. Pat. No. 4,566,452 is another exemplary prior art nebulizer structure. Farr discloses a nebulizer having a nebulizer top and a reservoir bottom which are threadably connectable to define a nebulizer housing. A gas jet extends from the reservoir bottom along a longitudinal axis of the reservoir bottom. A liquid spray nozzle surrounds the gas jet defining a passageway for liquid between the gas jet and the liquid nozzle. At the top of the gas jet is a gas orifice which leads into a space in fluid communication with the spray nozzle passage way. A second orifice in the top of the spray nozzle is axially aligned with the orifice in the gas jet. A diffuser is connected to the nebulizer top and spaced from the nozzle orifice with the nebulizer top and reservoir bottom threadably connected. As gas is caused to flow through the gas jet, a vacuum is formed in the space between the gas orifice and the nozzle orifice, drawing fluid for nebulization to the fluid nozzle orifice. Nebulized fluid impinges upon the diffuser, causing oversized droplets to stick to the diffuser and providing a finely nebulized mist for delivery to the lungs of a patient.
Farr addresses the problem of delivering substantially all of a measured amount of medication to the lungs of a patent by providing an extended side which projects outwardly from the spray nozzle and is adapted to fit snugly within the interior of the nebulizer bottom to define a space between the extended side and the inner surface of the side wall. This space functions as a conduit to deliver fluid to the fluid nozzle even when the nebulizer is tipped from its normal vertical orientation.
Lester, U.S. Pat. No. 5,512,341, is also directed to a structure for delivering substantially all of a measured volume of liquid to a patient even when the nebulizer is tipped from its vertical orientation. Lester '341 has the same basic housing structure of Farr and further discloses a plate that overlies the bottom of the nebulizer reservoir to define a capillary channel for delivering fluid to the nozzle when the nebulizer is tipped.
While the structures of Farr and Lester '341 are useful for delivering liquid medication through a nebulizer when the nebulizer is tipped from its vertical orientation, these structures are not without serious problems. Most notably, in order to maintain flow to the fluid nozzle, very close tolerances must be maintained within the nebulizers. This significantly increases the cost of the nebulizers and can create quality control problems.
The nebulizers disclosed in Farr and Lester '341 have a carrier gas supply connector which extends along a vertical axis downward from the reservoir bottom of the nebulizer housing. In order to enable the nebulizer bottom to be conveniently filled, Farr provides legs extending downward from the bottom of the housing to support the nebulizer housing in an upright position on a horizontal surface during loading. Similarly, Lester provides an annular collar around the carrier gas connector to maintain it upright during loading. One additional problem with this type of structure, however, is that during loading, the medical professional must be extremely careful not to tip the nebulizer bottom or expensive medications can be wasted. This problem can be exacerbated during emergency situations such as when the medical professional must move very quickly in a distracting environment.
The present invention is directed to overcoming one or more of the problems discussed above.